1. Field of the Invention
The present invention relates generally to methods for preventing thermal sensations when handling objects at non-body temperatures. More particularly, the present invention relates to methods for attenuating hot and cold thermal sensations when handling objects at non-body temperatures, while maintaining proper heat transfer into or from those objects.
2. Description of the Related Art
As the electrical power operating requirements within handheld and mobile electronics products continues to increase and the electronics enclosure volumes of handheld and mobile electronics products continues to decrease, it has become increasingly important within advanced handheld and mobile electronics products to provide adequate means for efficiently dissipating thermal loads which are generated in normal operation of those advanced handheld and mobile electronics products.
Handheld and mobile electronics products which are particularly susceptible to generating significant thermal loads whose dissipation is required for proper operation of those handheld and mobile electronics products typically include handheld and mobile electronics products whose operation employs high power microprocessor circuitry and/or high speed rigid disk drive operation. Such handheld and mobile electronics products typically include, but are not limited to, mobile computers and mobile data communications systems. Efficient dissipation of thermal loads from within electronics enclosure volumes of such electronics products is particularly desirable since elevated temperatures within such electronics enclosure volumes often facilitate premature microprocessing electrical circuitry failure and/or rigid disk drive electrical or mechanical failure.
In light of the continuing trend towards decreasing handheld and mobile electronics products weights and decreasing handheld and mobile electronics products electronics enclosure volumes, it is atypical within advanced handheld and mobile electronics products fabrication that active cooling means, such as fans, are employed to fully dissipate thermal loads from within electronics enclosure volumes within those advanced handheld and mobile electronics products. Rather, thermal load dissipation from within electronics enclosure volumes within handheld and mobile electronics products is typically largely undertaken through passive means, such as conduction, convection and radiation, while employing various electronics enclosure volume surfaces of the electronics products as surfaces through which thermal loads from within those electronics enclosure volumes may be dissipated.
Typical electronics enclosure volume surfaces through which thermal loads are dissipated within advanced handheld and mobile electronics products include but are not limited to electronics enclosure volume case surfaces, electronics enclosure volume keyboard surfaces and electronics enclosure volume keypad surfaces. The dissipation of thermal loads through such electronics enclosure volume surfaces is often largely governed by the thermal conductivity characteristics of a bulk material from which is formed the electronics enclosure volume surface. Common bulk materials which may be employed in forming electronics enclosure volume surfaces which assure efficient dissipation of thermal loads from within electronics enclosure volumes within handheld and mobile electronics products include metals, such as but not limited to aluminum, magnesium and alloys thereof, as well as several polymer materials, such as but not limited to carbon fiber filled polycarbonate polymer materials, acrylonitrile butadiene styrene (ABS) polymer materials and blends thereof
Although it is thus common in the art of handheld and mobile electronics products fabrication to employ electronics enclosure volume surfaces as a means to dissipate thermal loads from within electronics enclosure volumes incident to normal operation of those electronics products, dissipation of thermal loads through electronics enclosure volume surfaces within advanced handheld and mobile electronics products is not entirely without problems within advanced handheld and mobile electronics products fabrication.
With regard to handheld and mobile electronics products which require dissipation of particularly high levels of thermal power within exceedingly limited electronics enclosure volume surface areas (ie: a thermal power dissipation of greater than about 0.03 watts per square centimeter of electronics enclosure surface area), electronics enclosure volume surfaces within those advanced handheld and mobile electronics products may readily reach temperatures of greater than about 60 degrees centigrade. Such elevated temperatures detract from a normally desirable, comfortable and safe operation of those handheld and mobile electronics products.
It is thus desirable in the art of handheld and mobile electronics products fabrication to provide methods and materials through which may be fabricated handheld and mobile electronics products which simultaneously exhibit: (1) efficient dissipation of thermal loads through electronics enclosure volume surfaces of those handheld and mobile electronics products when operating those handheld and mobile electronics products, and (2) substantial attenuation of heat sensation upon human contact of those electronics enclosure volume surfaces when handling and operating those handheld and mobile electronics products. It is towards these seemingly contradictory goals that the present invention is most specifically directed.
In a more general sense, the present invention is also directed towards providing methods and materials through which may be fabricated thermally conductive objects, such as but not limited to handheld and mobile electronics products, as well as other electronics products and non-electronics products, which simultaneously exhibit: (1) efficient dissipation of thermal loads into or from those thermally conductive objects through surfaces of those thermally conductive objects; and (2) substantial attenuation of thermal sensation upon contact of the surfaces of those thermally conductive objects when handling and operating those thermally conductive objects. It is towards these analogously contradictory goals that the present invention is more generally directed.
A first object of the present invention is to provide a method for fabricating an object, and an object fabricated in accord with the method, where the method provides for efficient dissipation of a thermal load into or from the object through a surface of the object.
A second object of the present invention is to provide a method in accord with the first object of the present invention, where there is simultaneously attenuated a thermal sensation when contacting the surface of the object with a body when handling or operating the object.
A third object of the present invention is to provide a method in accord with the first object of the present invention or the second object of the present invention, where the object is a handheld or mobile electronics product.
A fourth object of the present invention is to provide a method in accord with the first object of the present invention, the second object of the present invention or the third object of the present invention, which method is readily manufacturable.
In accord with the objects of the present invention, there is provided by the present invention a method for fabricating an object, and an object fabricated in accord with the method. To practice the method of the present invention, there is first provided a substrate having a first surface subject to handling. There is then formed upon the first surface of the substrate a coating. The coating has an optimally low density, an optimally low thermal conductivity, an optimally low heat capacity and an optimally minimal thickness such that when the substrate having the coating formed thereupon is equilibrated at a non-body temperature differing from a body temperature and the coating is subsequently contacted with a body at the body temperature during handling, the temperature of the surface of the coating at a contact point of the body with the coating changes precipitously to a temperature near the body temperature and subsequently partially returns towards the non-body temperature at a rate which permits handling of the substrate at the location of the coating by the body with attenuated thermal sensation. In addition, the coating simultaneously also minimally attenuates a steady state heat transfer with respect to the substrate in comparison with an otherwise equivalent substrate absent the coating.
The method of the present invention contemplates an object fabricated in accord with the method of the present invention.
The present invention provides a method for fabricating an object while: (1) providing an efficient thermal dissipation of a thermal load into or from the object through a surface of the object, while simultaneously; (2) attenuating a thermal sensation when contacting the object in normal handling or operation of the object through the surface of the object. The method of the present invention realizes the foregoing objects by forming upon a first surface of a substrate from which is formed an object a coating. The first surface of the substrate is subject to handling. The coating has an optimally low density, an optimally low thermal conductivity, an optimally low heat capacity and an optimally minimal thickness such that there is provided: (1) an efficient thermal dissipation of a thermal load into or from the substrate at the location of the coating, while simultaneously; (2) attenuating a thermal sensation when contacting the coating by a body in normal handling or operation of the substrate at the location of the coating.
The method of the present invention may be employed where the object is a handheld or mobile electronics product. The method of the present invention does not discriminate with respect to the nature of the object for which there may be simultaneously: (1) provided an efficient thermal dissipation of a thermal load into or from the object through a surface of the object, and; (2) attenuated a thermal sensation when contacting the object with a body in normal handling or operation of the object through the surface of the object. Thus, although the method of the present invention is most likely to provide value when simultaneously: (1) providing an efficient thermal dissipation of a thermal load from within a handheld or mobile electronics product electronics enclosure volume through an electronics enclosure volume surface of the handheld or mobile electronics product, and; (2) attenuating a thermal sensation when contacting the handheld or mobile electronics product electronics enclosure volume surface with a body in normal handling or operation of the handheld or mobile electronics product, the method of the present invention may also be employed in fabricating objects other than handheld and mobile electronics products. The method of the present invention may in general be employed in fabricating objects including but not limited to handheld electronics products, mobile electronics products, other electronics products, consumer products, industrial products and medical instruments.
The method of the present invention is readily manufacturable. As is disclosed within the Description of the Preferred Embodiment, methods and materials through which coatings may be formed upon substrates with optimally low densities, optimally low thermal conductivities, optimally low heat capacities and optimally minimal thicknesses to realize the objects of the present invention are accessible through coatings technology which may be employed within at least handheld and mobile electronics products electronics enclosure volume surface fabrication, and presumable also other object fabrication. Thus, the method of the present invention, and an object fabricated in accord with the method of the present invention, is readily manufacturable.